1. Field of the Invention
The invention relates to a method of determining the rotational speed of a machine having a drive into which a setpoint value for the rotational speed has been introduced, and a rotational-speed sensor from which a measured actual value is obtainable.
2. Description of the Related Art
Rotational-speed sensors have become known heretofore for measuring the rotational speed of a machine, particularly for purposes of control. If errors occur in this connection, faulty control of the machine may result. Frequently, incremental pulse generators are used as rotational-speed sensors, and angular-speed pulses generated by the incremental pulse generators are counted. It is possible, in this connection for spurious pulses to be produced, for example, due to interference in connecting leads between the incremental pulse generator and a control unit. The reason for spurious pulses may lie also in the incremental pulse generator itself if, for example, opaque particles penetrate into an optical incremental pulse generator. Such spurious pulses may likewise result in falsification of the measured data.
It is accordingly an object of the invention of the instant application to provide a method and device with increased reliability in the determination of the rotational speed of a machine.